Fluid-pump



N. A. NELSON.

FLUID PUMP.

APPLlCATION FILED APR. 19, I920.

1,370,903. Patented Mar. 8, 1921.

fl I S WUK/WOi/ b? Nels A- Nels on UNITED STATES PATENT OFFICE.

NELS A. NELSON, OF SAUKVILLE, WISCONSIN, ASSIGNOR 0F ONE-HALF TO GEORGE W.

' BOLLOW, OF MILWAUKEE, WISCONSIN.

FLUID-PUMP.

Specification of Letters Patent.

Patented ManS, 1921..

Application filed April 19, 1920. Serial No. 375,055.

T 0 all whom it may concern:

Be it known that I, NELS A. NELSON, a subject of the King of Norway, and resident of Saukville, in the county of Ozaukee and State of Wisconsin, have invented certain new and useful Improvements in Fluid- Pumps; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention has for its object to provide a simple, economical and effective doubleacting fluid pump, the same being particularly adapted for use in inflating pneumatic vehicle tires.

In the accompanying drawing:

Figure 1 represents a side elevation, partly in section of a pump embodying the features of my invention, and

Fig. 2 an enlarged detail sectional view of the valve mechanism.

Referring by characters to the drawings, 1 represents a pum' cylinder having at its lower end a retaining foot. The cylinder" has mounted therein a hollow piston rod 2 which extends throughout a suitable gland at the top of the cylinder and carries a handle 3, for reciprocating the same. The

' lower end of the hollow piston rod is closed by a cap 4, constituting a stop and is provided with sets of spaced radially disposed ports 5 and 6 as shown. These ports are arranged to be controlled by a reciprocating sleeve 7 which is mounted upon the piston rod, the movement of the same being limited by the cap 4 in one direction and a collar 4: fixed to the rod in the opposite direction.

The sleeve is provided with an upper set of ports 8 and a lower set 8, which are spaced at a distance apart slightly less than the ports 5 and 6.

Thus when the sleeve is moved downwardly the ports 8 will register with the ports 5 and when moved upwardly the ports 8 will register with the ports 6.

The sleeve 7 carries a piston head 9 of any standard type, the same being held in position by clamp nuts 10 and 10, which are in threaded union with the exteriorly threaded face of the sleeve.

The upper end of the hollow piston rod is threaded for the reception of a vented cap 11 through which air is admitted to the rod and by means of which cap the handle 3 is also confined. By providing the cap with ports as shown for intake of air liability of closing said ports by the hands of avoided. I

The retaining foot has a shank portion that s in threaded union with the end of the cylinder whereby the latter is closed and said head is also provided with a channel 12, which communicates with a delivery pipe 13 that also communicates with the upper end of the cylinder. This pipe carries check valves 14 and 15 at its ends to prevent back flow of air wh n the pump is. functioning to supply the fluid, it being no lerstood that the pipe 13 has a nozzle 13 to which is attached any suitable supply pipe, preferably in the form of a flexible hose.

While I have shown and described the pipe 13 as being a separate element, obviously this pipe may be in the form of a channel or duct cast integrally with the cylinder. From the foregoing description it will be noted that when the operator lifts the piston rod upwardly the piston head 9 and its ports will move downwardly whereby the companion ports 8 and 5 will register.

' tion to the ports 6 and thus any air in the upper portion of the cylinder will be expelled through the pipe16 to the nine 13 to the point of delivery and owing to the check valves 14 and 15 this air will be prevented from returning to the cylinder. i

It follows that upon the down stroke of the hollow piston rod the action is reversed whereby the air which has previously entered the lower portion of the cylinder will be expelled in the same manner.

Thus it will be seen that a simple economical and durable double-acting pump is produced whereby the maximum volume of air can be compressed with a maximum application of power.

I claim:

A double acting pump piston comprising a hollow piston rod having radially disposed spaced ports at its lower end, stops carried by the piston rod above and below the spaced ports, an exteriorly threaded sleeve reciprocativelv mounted upon the lower .end of the piston rod between the limited in its movement in opposite directions by the aforesaid rod stops, a piston head in threaded union with the Sleeve between its ports and a valve controlled intake port at the upper end of the hollow piston rod.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee in the county of Milwaukee and State of Wisconsin.

NELS A. NELSON. 

